Lisa Robin Kelly, best known for playing Eric’s older sister Laurie on the first five seasons of That ’70s Show, has died, EW has confirmed.

Kelly passed away last night at a rehab facility, her agent, Craig Wyckoff, tells EW. The 43-year-old had voluntarily checked into treatment, “where she was battling the addiction problems that have plagued her these past few years.” (Most recently, she was arrested on suspicion of drunken driving this past June.)

“I spoke to her on Monday and she was hopeful and confident, looking forward to putting this part of her life behind her,” Wyckoff said in an email. “Last night she lost the battle.”